Integrated tunable inductors

Abstract

An integrated inductor can be tunable via a control current which alters the magnetic flux density in a permeable magnetic material. The resulting inductor can be adjusted in-circuit, and may be suitable for applications such as dc-dc converters, RF circuits, or filters requiring operation at high frequencies and across wide bandwidths.

Whatis claimed is: 
     
         1 . An integrated tunable inductor, comprising:
 a substrate configured to receive an inductor;   an inductor located proximate to the substrate;   a magnetic material located proximate to the inductor;   a first control line located proximate to the magnetic material, wherein the first control line is configured for the conduction of an electric current; and   a controller configured to tune the magnitude of the electric current.   
     
     
         2 . The system of  claim 1 , wherein the substrate comprises quartz. 
     
     
         3 . The system of  claim 1 , wherein the first control line is oriented to induce an electromagnetic field parallel to an axis of the magnetic material. 
     
     
         4 . The system of  claim 1 , wherein the first control line is oriented to induce an electromagnetic field parallel to an easy axis of the magnetic material. 
     
     
         5 . The system of  claim 1 , wherein the first control line is oriented to induce an electromagnetic field parallel to a hard axis of the magnetic material. 
     
     
         6 . The system of  claim 1  wherein the inductor is a planar inductor. 
     
     
         7 . The system of  claim 1 , further comprising a second control line located proximate to the inductor, wherein the first control line is oriented parallel to a hard axis of the magnetic material, and wherein the second control line is oriented parallel to an easy axis of the magnetic material. 
     
     
         8 . The system of  claim 1 , wherein the magnetic material comprises a continuous ring surrounding a portion of the inductor. 
     
     
         9 . The system of  claim 1 , wherein the magnetic material comprises a bar structure traversing a portion of the inductor. 
     
     
         10 . The system of  claim 5 , wherein the planar inductor comprises a concentric planar spiral. 
     
     
         11 . The system of  claim 1 , wherein the inductor comprises at least one of: a strip line structure, a solenoidal structure, a toroidal structure, a finger structure, or a bar structure. 
     
     
         12 . The system of  claim 1 , wherein the magnetic material comprises CoZrTaB. 
     
     
         13 . The system of  claim 1 , wherein the magnetic material is electrically insulated from the inductor by a layer of insulating material. 
     
     
         14 . The system of  claim 13 , wherein the insulating material is polyamide. 
     
     
         15 . A method of varying the inductance of an integrated tunable inductor, the method comprising:
 passing a first current through a first control line located proximate to an inductor;   inducing a first electromagnetic field to radiate from the control line and traverse a first magnetic material located proximate to the inductor, wherein the first magnetic material has a variable magnetic flux density;   varying the magnitude of the first current in response to the inducing a first electromagnetic field;   changing the variable magnetic flux density of the magnetic material in response to the varying the magnitude of the first current; and   altering the capacity of the inductor to store energy in a second electromagnetic field radiating from the inductor and traversing the first magnetic material in response to the changing the variable magnetic flux density.   
     
     
         16 . A method of manufacturing a planar inductor, the method comprising:
 configuring a substrate to receive an inductor;   forming an inductor on the substrate by depositing a conductive material on the substrate;   positioning a first control line proximate to the inductor, wherein the first control line is configured for the conduction of a first electric current;   connecting a controller in electrical communication with the first control line; and   configuring the controller to tune the magnitude of the first electric current.   
     
     
         17 . The method of  claim 16 , further comprising:
 positioning a second control line proximate to the inductor, wherein the second control line is configured for the conduction of a second electric current;   connecting the controller in electrical communication with the second control line; and   configuring the controller to tune the magnitude of the second electric current.   
     
     
         18 . The method of  claim 16 , further comprising depositing an insulating material between the inductor and the first control line. 
     
     
         19 . The method of  claim 16 , wherein the depositing a conductive material on the substrate comprises transferring material to the substrate by magnetron sputtering. 
     
     
         20 . The method of  claim 19 , further comprising:
 applying an external DC magnetic field during the magnetron sputtering; and   configuring the conductive material to exhibit uniaxial magnetic anisotropy in response to the applying an external DC magnetic field.